It appears the occupants of a bronze SUV and a silver hatchback were shooting at each other. Kelly didn't know if the gunfire started on the highway, but said that shell casings were found on the off-ramp.

He said investigators haven't determined whether it was a road rage incident or a targeted shooting.

The Redwood Road off-ramp remains closed for the investigation Wednesday afternoon. Kelly said deputies hope to have it cleared soon so there is minimal traffic disruption.